Battery charger



E. W. ENGLE BATTERY CHARGER ,3 sheets sheet 1 Original Fil Aug.

May 27 1924.

E. W. ENGLE BATTERY CHARGER Original Fil,ed Aug. 19 1922 s Sheets-Sheet 2 May 27 1924; 1,495,532

E. w. ENGLE BATTERY. CHARGER,

(ori inal Filed Aug. 19, 1922, 3She0ts-Sh0et 5 Patented May 271 1924.

UNITED STATES PATENT OFFICE,

EDGAER. W. ENGLE, OF LAKE FOREST, ILLINOIS, A SS IGNOR T FANSTEEL PRODUCTS COMPANY, INC., 01? NORTH CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

BATTERY CHARGER.

continuation of applications Serial No. 582,851; filedAugust 19, 1922, and Serial No. 668,938, filed October 16, 1923. This application filed March 27, 1924. Serial No. 702,278.

To all whom it may concern: I

Be it known that'l, EDGAR 1V. ENGLE, a citizen of the United States. and resident of Lake Forest, in the county of Lake and State of Illinois, have invented a certain new and useful Improvement in Battery Chargers, of which the following is a full, clear, concise, andeXact description, reference being had to the accompanying drawings, forming .a

' part of this specification.

This invention relates to a battery charger or rectifier, apd particularly to a self-contained device of this kind adapted to be used mto charge from a source of alternating cur- It isbelieved the inventionwill be under" stood most readily from a detailed description thereof taken in connection with the accompanying drawings, in which Figure fl'gl. is a plan view of the complete charging unit;

Figure 2 is a section on line 22 of Figure 1;

Figure 3 is a section on line 3-3 of Figure 1;

Figure i is a section on line H of Figure 1 Figure. 5 schematically indicates the circuit eonnectioiis of the various elements of the battery charger, and \V V Figure 6 schematically indicates the con struction and arrangement of the trans. former core .and coil Referring now' to the drawings, in ,which like reference characters indica-te'lik parts in the several views, 10 indicates the charger container of wood or other suitable material. The container 10 is provided with a bail l1 rent storage batteries of the character used gust 19, 21922, and 668,938, filed October 16,

and the supporting legs or pads 12 of rubber or other suitable material.

trally thereof with the transversely extending strip 13 which forms apartial part tion between the portion of the container in which is positioned the .rectiiier cell and the portion in which the transformer and similar elements are positioned.

The rectifying element of the present in The container ispro lded at the top and substantially cen-- aussuu vention consists of an anode 14 of lead, and

a cathode 15 of tantalum in an electrolyte, preferably of dilute acid, as sulphuric acid. Sulphuric acid of 1.25 specific gravity hasv been found satisfactory. It has been found that tantalum has the property of permitting current to flow from the electrolyte to the tantalum electrode but preventing the flow of electricity in the reverse direction. The electrolyte is confined in a cell 16 of lead in the present embodiment of the invention, al-

though it may be of other satisfactory ma terial ashard rubber. The anode 14 preferably has a small amount of antimony mixed with the lead in order to make it more resistive to the action of the electrolyte. If a hard rubber cell is employed, it may be fitted within a casing of lead or similar material having heat radiating flanges.

Fixed to the bottom of the cell 16, or integral therewith, are the downwardly extending supporting members 17. each of which is provided with a pair of laterally extending feet 18 secured to the bottom of the container 10 by means, of the bolts 19. The sides of the cell 16 are provided with the laterally extending heat radiating wings or flanges 20 which act to position the cell 16 between one side of the container 10 and the partition member 13. The cell is positioned against movement lengthwise thereof by the ends of the cell engaging the container. Positioned between pairs of the flanges 20 are the laterallyv extending shelves 22, each pair of which is provided with aligned openings 23 within which are fixed the insulator 24 of porcelain or other desired material. a

5 The top of the cell 16 is provided with a cover 25 of hard rubber or other suitable material. The plate 25 is provided with a filler cap opening 26 within whichis inserted the cap 27 having the vent openings 28 there in. The cover 25 is also provided with the tapered openings 29, and 30. Positioned within the openingor recess 29 is the sleeve 32 of hard rubber or other suitable material. The sleeve 32 is externally threaded atits lower end and is provided with the nut by means of which the sleeve 32is firmly due to contact with the mould.

secured in position. Extending longitudinally of the sleeve 82 is the recess 34 which terminates at the lower end thereof in the rectangular opening-35 through which the cathode 15 extends. The upper end of the cathode 15 is cast in or otherwise secured to the .lower end'of the terminal post 31. A I satisfactory manner of securingithe tantalum As this inner'molten metal hardens, it

tends to expand, but being restrained by the outer shell, the end of the cathode is firmly gripped by the lead. The terminal p'ost 31 is provided with an'annular ridge 36. The post. 31 and the cathode 15 are secured in position as follows:

Therecess 34 having been. filled with an acid-resisting compound, as asphaltic cenient, the lower ,end of the post 31 is forced into the top of the recess 34 before the cement has hardened. After the post 31 has been put in position, as just described, the top. portion of the" recess 2,9v is also filled with battery sealing cement in order firmly to anchor the post 31. Surrounding the-cathode 15, adjacent to the lower end. thereof, is a block-37 of acidresisting niaterial, as soft rubber, which is maintained in position by means of the portions 38 turned from the lower endof the cathode 15.

The bottoin of the cell 16, adjacent to one end thereof, is provided with the annular flange 39 within which is positioned the lower end of the anode 14, a collar 40 of insulating material, as hard rubber, being providedgbet-ween the flange39 and the anode14 in order to prevent engagement.

The anode 14 is provided with an enlarged' portion or head 41 which engages the top of fthe collar 40 in order to support the anode. The upper end of the anode 14 passes upwardly through the tapered recess 30 and is provided with a flange .42 which engages the bottom of the cover-25. The

space within the recess 3O about the-upper end 43 of the anode 14 is filled with an acid-resisting cement, as asphaltic cement.

cesses Secured to the upper ends of the terminal posts 31 and 43. respectively, are the rods 44 and 45 of iead or other conducting material which extends iaterally and then downwardly through the insulating sleeves 24.

The transformer; consists of the core member formed of the E-shaped laminations 46 and 47 about the tongues of which are positioned the primary coil 48 and the secondary coil 49. The transformer shown comprises a primary of about 440 turns of No. 22 wire, and a secondary of about 71 turns of No. 15 wire. This transformer when joined to a 110' volt light circuit gives an output voltage of'approximately 18%; volts.

Positioned on. opposite sides of the laminations 46 and 47 are the clamping members 50 which are held firmly in engagement with the laminations'by means of the bolts The lower ends of the members 50 are provided with the laterally extending perforated portions 52 which are secured to thebottomof the container 10 by means of the screws 53. The upper ends of the clamping members 50 are provided with the laterally extending portions 54, each of which is provided with'a screw threaded opening 55. Positioned on the laterally extending portions 54 is a plate 56 of bakelite. fibre, or other suitable insulating ma tcrial which is secured to the portions'54 by meansof the screws 57 which pass downwardly through the plate 56 andinto the screw threaded openings 55. The fuse clips 1 58 and 59 are secured to the-top of the plate 56by'means of the bolts 60 and 61, re-

spectively,pro\-'ided with the securing nuts 62 and 63. I

Fixed to the'transfonner core, in any desired manner, or otherwise mounted, is a sleeve 65 of porcelain or other suitable insulating material, within which is spirally arranged a limiting resistance coil 66, preferably of nickel wire. The wire 66 may be approximately .0257 in diameter, and about 164 4 in length. After the coil 66 has been placed in position, the ends of the sleeve 65 are closed by some suitable mineral cement. This acts partially'to retain the heat generated by the coil and causes its properties to be more. constant. been found preferable because it offers in- Nickel wire has creased resistance upon increase of the curend of the wire 66 is joined to-the fuse clip 58 by means of the conductor 67, theother end being joined to the secondary 68 ofthe transformer by means of the conduct-or 69 (see Figures 4 and 5,). The other fuse clip 59 is joined to the rod 44 connected to the tantalum cathode by means of theconductor 70. Positioned within the clips 58 and 59 is the ordinary cartridge fuse 71 such as is employed in connection with the electrical scribed,- reference being made to Figure 5.

The primary 75 of the transformer is joined by means of the conductor pair.76 to the of the conductor 'The other end of ordinary plug 77 which is adapted to be inserted in the socket 78, the terminals of which arc'joined to the conductors 79 and 80 of-the'ordinary light circuit of approximately 110 volts alternating current. One end of the secondary 68 is joined by means 81 to the terminal clip 82. the secondary 68 is joined by theconductor 69 to the resistance 66. as previously described. The opposite end of the resistance 66 is connected by the con-;

ductor 67 to one end of the fuse 71, the opposite end of the fuse 71 being joined by conductor'i'O to the tantalum cathode 15. The lead anode isjoined by the conductor 83 to'the terminal clip 84. The winding 68. 'thelimiting coili66 ,a'nd' the resistance of the transformer operate to limit the flow of current toa maximum of approximately 3;;

amperes direct current. v By reference'to Figure 2', it will be noted that the conductor 83 is joined to the lower end of the rod 45 connected to the anode 14 ""conductor 81 which extends from one end and extends laterally and then upwardly through the opening 85 in the plate 56. The

of the secondary 68 passes upwardly and out through the opening 86 inthe plate 56. The pair 76, the conductors of which are joined to the opposite ends of the primary 7 5, passes upwardly-through the opening 87 in the plate 56. The-p1ate5'6, in. addition to theopenings 85, 8'6 and87,"is provided with a plurality of openings 88. The sides of the container v1O, adjacent to the bottom thereof, are provided with the openings 89.

As shown, the openings 89 are provided only on two opposite sides of the box, but, if desired, they maybe provided" on all four It will be noted that the cell 16 and 56,'and also upwardly-between the wings or flanges 20 of the cell,'thus greatly assisting in maintaining the charger cool whilev it is in use, which is quite essential to the most satisfactory operation:

It has been found that when the transformer employed withthe rectifier, such as herein shown, is designed to give a certain charging rate, oftentimes the charging rate of the rectifier will suddenly change. This is believed to be due generally to some foreign matter having been introduced into the electrolyte.

phosphoric acid, this tendency of the charging rate to fluctuate is largely obviated.

Very good results are obtained by adding from one-half to one part per thousand of iron. The iron may be added as metallic iron, but is preferably introduced in theform of ferrous sulphate. It has been found Applicant has discovered that when a small quantity of metallic impurity, as for instance iron. is added to'the-electrolyte of dilute acid. such as sulphuric or that a slight excess of iron may be added to the electrolyte without injuriously affecting the rectifier. In practice the iron is introduced by adding aboutone gram of ferrous sulphate crystals to each 100 cubic centimeters of the electrolyte. Somewhat larger or'smaller quantities of iron maybe added with varying results. When the iron impurity is added to the-electrolyte. the charging rate of the rectifier is materially increased. usually in the neighborhood of 50%, although sometimes much larger increases are brought'about. In addition to increasing the charging rate, the addition of the iron to the electrolyte causes the heating effect of the-rectifier to be relatively decreased. This is probably due to the iron acting to decrease the internal resistance of the rectifier.

In addition to increasing the chargingrate and decreasing the relative heating effect, the introduction of the metallic impurity :acts to render the rectifier m'ore stable I .or constant'in' its charging rate.

While iron has been found to give very good results, when introduced into the electrolyte. applicant has discovered-that certain other metallic im'purities, as copper or silver, have,'to' a certain extent, the same efiect as iron when addedto the electrolyte.

It has been found that a rectifier, constructed as above described will sometimes explode under exceptional circumstances, as when subjected to an-overload. This may be due to the union of the hydrogen and oxygen liberated atthe electrodes. It has been discovered that if a small amount of heavy oil is poured into the rectifier'cell, the explosion ofthe cell is absolutely prevented; About two teasp'oonfuls of pure heavy liquid petrolatum has been extensively employed with satisfactory results. I The heavy oil forms a film over thle top of the elec trolyte and also an insuating film on the electrodes. This fihn. may act to suppress sparks which otherwise would occur at one rate is about a} ampere.-

the electrolyte retards the escape'of the gas responsible for the explosions. At any rate, when the oil is employed the explosions are absolutely prevented: The oil film, in addition to preventing explosions, practically prevents fuming of the electrolyte and greatly reduces evaporation, v

The battery charger herein disclosedhas an electric power circuit, the voltage 'of' 'which varies greatly from 110 volts, the

transformer should be altered to give an output current similar to that herein "described. I

While in the drawings and inthe above description, applicant has disclosed but a single set of details which show. the preferred embodiment of his invention, it is to be understood that variousmodific'ations are contemplated andthe invention should, therefore, be limited merely bythe scope bf the appended claims.-

Having thus described my invention, what I -'I claim as new and desire to secure by Letters Patent of the United States is:

1. An electrolytic rectifier for producing unidircctionalcurrent from a source of alternating ciirrent, said rectifier having an electrode of tantalum and an electrode of a non-filming conductor in an acid 'electrolyte." e

.2. In a. battery c harger, w an electrolytic rectifier having an electrode of tantalum, an electrode 'of'lead, and an electrqlytegof dilute sulphuric acid.

"3. In .a. battery charger 31' an electrolytic rectifier having an electrode of tantalum in an electrolyte ofdilute sulphuric acid.

4. In a battery charger, an electrolytic rectifier including .a tantalum electrode in a dilute sulfuric acid electrolyte having a small quantity of metallic impurity added thereto.

5. In a battery charger, an electrolytic rectifier including a tantalum cathode in an :acid electrolyte, a cell containing saidelectrolyte, a'terminal post of lead-antimony composition for said cathode, one end of said cathode being'cast into said terminal post, a cover for-said cell provided with a sleeve in which are positioned the adjoining ends of said cathode and'post, and an acid resisting cement Within'said sleeve about said cathode below said post.

In witness whereof, I hereunto subscribe my name this-25 day of March, 1924.

- EDGAR 'WIENGLE.

Witnesses: r v

DOGMAR PETERSON, HELEN G. DREVNIAK. 

